16 / 116
A
sano
LYJ
et
al
.
512
R
ev
A
ssoc
M
ed
B
ras
2014; 60(6):512-517
Guidelines In focus
Stress fractures in the foot and ankle of athletes
F
ratura
por
estresse
no
pé
e
tornozelo
de
atletas
Authors:
Asano LYJ, Duarte Jr. A, Silva APS
http://dx.doi.org/10.1590/1806-9282.60.06.006The Guidelines Project, an initiative of the Brazilian Medical Association, aims to combine information from the medical field in order to standar-
dize procedures to assist the reasoning and decision-making of doctors.
The information provided through this project must be assessed and criticized by the physician responsible for the conduct that will be adopted, de-
pending on the conditions and the clinical status of each patient.
D
escription
of
the
evidence
collection
method
To develop this guideline, the Medline electronic databa-
se (1966 to 2012) was consulted via PubMed, as a primary
base. The search for evidence came from actual clinical
scenarios and used keywords (MeSH terms) grouped in
the following syntax: “Stress fractures”, “Foot”, “Ankle”,
“Athletes”, “Professional”, “Military recruit”, “Immobili-
zation
”
, “Physiotherapy”, “Rest”, “Rehabilitation”, “Con-
ventional
treatment”, “Surgery
treatment”. The articles
were selected by orthopedic specialists after critical eva-
luation of the strength of scientific evidence, and publi-
cations of greatest strength were used for recommenda-
tion. The guidelines were drawn from group discussion.
The entire text was reviewed by a group specializing in
evidence-based clinical guidelines.
G
rade
of
recommendation
and
strength
of
evidence
A.
Experimental or observational studies of higher con-
sistency.
B.
Experimental or observational studies of lower con-
sistency.
C.
Case reports (non-controlled studies).
D.
Opinions without critical evaluation, based on con-
sensus, physiological studies, or animal models.
O
bjective
The target audience of this guideline includes orthope-
dists, physiatrists and sports doctors in order to guide
the diagnosis and treatment of athletes with stress frac-
tures in the foot and ankle.
C
onflict
of
interest
No conflict of interest informed.
I
ntroduction
Stress fractures were described for the first time in 1855
by Breihaupt among soldiers reporting plantar pain and
edema following long marches.
1
For athletes, the first cli-
nical description was given by Devas in 1958, based so-
lely on the results of simple X-rays.
2
Stress injuries are
common among athletes and military recruits, accoun-
ting for approximately 10% of all orthopedic injuries.
3
It is defined as a solution for partial or complete con-
tinuity of a bone as a result of excessive or repeated loads,
at submaximal intensity, resulting in greater reabsorp-
tion faced with an insufficient formation of bone tissue.
1
Although stress fractures may affect all types of bone
tissue, they are more common in bones that support body-
weight, especially those in the lower limbs (tibia, 49%; tar-
sal bones, 25%; metatarsals, 9%).
3
Studies on runners reveal
a higher incidence of stress fractures in the tibia, followed
by the metatarsals, fibula, femur and navicular bone.
4,5
The locations of stress fractures vary from sport to sport.
Runners may develop a stress fracture of the medial malleo-
lus, the distal end of the fibula, calcaneus, lesser metatarsal,
andmedial sesamoid bone. Classical ballet, aerobic gymnas-
tics, tennis and volleyball athletes mainly present stress frac-
tures in the navicular and sesamoid bones. Basketball ath-
letes have a prominence of the medial malleolus, navicular
bone and metatarsal stress fractures, while for footballers
lesser metatarsal fractures are more common.
6,7,8
From a biomechanical point of view, fatigue fractures
are the result of specific, cyclical and repetitive muscle ac-
tion until exhaustion, with load transfer to the bone excee-
ding its adaptation capacity.
8,10
The shear and compression
forces stimulate bone transformation according to Wolff’s
law, that is, the compression forces promote osteoblast ac-
tivity and bone deposition leading to a strengthening of
bone structures, adapting to the applied load, while shear
forces lead to the reverse process of bone resorption by
stimulating osteoclast activity. As a result, the majority of
stress fractures are located in the areas of shear stress.
4,5,8